Android Application : In-app Billing Example with Utility. Test app at https://play.google.com/store/apps/details?id=com.ethanf.in_app_billing_ex2

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/btnQuery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Query" />

    <Button
        android:id="@+id/btnPurchase"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/btnQuery"
        android:text="Purchase" />

    <Button
        android:id="@+id/btnConsume"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/btnPurchase"
        android:text="Consume" />

</RelativeLayout>

MainActivity.java

package com.ethanf.in_app_billing_ex2;

import com.ethanf.in_app_billing_ex2.util.IabHelper;
import com.ethanf.in_app_billing_ex2.util.Inventory;
import com.ethanf.in_app_billing_ex2.util.IabResult;
import com.ethanf.in_app_billing_ex2.util.Purchase;
import com.ethanf.in_app_billing_ex2.util.SkuDetails;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
	private Context context;
	private String tag;

	private IabHelper mHelper;
	private final String base64PublicKey = "<public key>";
	private boolean isSetup;

	// ProductID
	private final String productID = "android.test.purchased";	// Test Product ID by Google

	// View
	private Button btnQuery, btnPurchase, btnConsume;

	// Purchase
	private Purchase purchaseOwned;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		// Context
		context = getApplicationContext();

		// log tag
		tag = "in_app_billing_ex2";

		// Helper
		mHelper = new IabHelper(context, base64PublicKey);
//		mHelper.enableDebugLogging(true);
		mHelper.enableDebugLogging(true, tag);

		// Assign View
		btnQuery    = (Button) findViewById(R.id.btnQuery);
		btnPurchase = (Button) findViewById(R.id.btnPurchase);
		btnConsume  = (Button) findViewById(R.id.btnConsume);

		try {
			mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
				@Override
				public void onIabSetupFinished(IabResult result) {
					boolean blnSuccess = result.isSuccess();
					boolean blnFail = result.isFailure();

					isSetup = blnSuccess;

					Toast.makeText(context, "mHelper.startSetup() - blnSuccess return " + String.valueOf(blnSuccess), Toast.LENGTH_SHORT).show();
					Toast.makeText(context, "mHelper.startSetup() - blnFail return " + String.valueOf(blnFail), Toast.LENGTH_SHORT).show();
					Log.i(tag, "mHelper.startSetup() ...");
					Log.i(tag, "	- blnSuccess return " + String.valueOf(blnSuccess));
					Log.i(tag, "	- blnFail return " + String.valueOf(blnFail));
				}
			});
		} catch (Exception e) {
			e.printStackTrace();

			isSetup = false;
			Toast.makeText(context, "mHelper.startSetup() - fail!", Toast.LENGTH_SHORT).show();
			Log.w(tag, "mHelper.startSetup() - fail!");
		}

		btnQuery.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				if (!isSetup) return;

				mHelper.queryInventoryAsync(new IabHelper.QueryInventoryFinishedListener() {
					@Override
					public void onQueryInventoryFinished(IabResult result, Inventory inv) {
						boolean blnSuccess = result.isSuccess();
						boolean blnFail = result.isFailure();

						Toast.makeText(context, "mHelper.queryInventoryAsync() - blnSuccess return " + String.valueOf(blnSuccess), Toast.LENGTH_SHORT).show();
						Toast.makeText(context, "mHelper.queryInventoryAsync() - blnFail return " + String.valueOf(blnFail), Toast.LENGTH_SHORT).show();
						Log.i(tag, "mHelper.queryInventoryAsync() ...");
						Log.i(tag, "	- blnSuccess return " + String.valueOf(blnSuccess));
						Log.i(tag, "	- blnFail return " + String.valueOf(blnFail));

						if (!blnSuccess) return;

						Log.i(tag, "	- inv.hasPurchase()   = " + inv.hasPurchase(productID));
						Log.i(tag, "	- inv.getPurchase()   = " + inv.getPurchase(productID));
						Log.i(tag, "	- inv.hasDetails()    = " + inv.hasDetails(productID));
						Log.i(tag, "	- inv.getSkuDetails() = " + inv.getSkuDetails(productID));

						if (!inv.hasPurchase(productID)) return;

						purchaseOwned = inv.getPurchase(productID);

						Log.i(tag, "	- inv.getPurchase() ...");
						Log.i(tag, "		.getDeveloperPayload() = " + purchaseOwned.getDeveloperPayload());
						Log.i(tag, "		.getItemType()         = " + purchaseOwned.getItemType());
						Log.i(tag, "		.getOrderId()          = " + purchaseOwned.getOrderId());
						Log.i(tag, "		.getOriginalJson()     = " + purchaseOwned.getOriginalJson());
						Log.i(tag, "		.getPackageName()      = " + purchaseOwned.getPackageName());
						Log.i(tag, "		.getPurchaseState()    = " + String.valueOf(purchaseOwned.getPurchaseState()));
						Log.i(tag, "		.getPurchaseTime()     = " + String.valueOf(purchaseOwned.getPurchaseTime()));
						Log.i(tag, "		.getSignature()        = " + purchaseOwned.getSignature());
						Log.i(tag, "		.getSku()              = " + purchaseOwned.getSku());
						Log.i(tag, "		.getToken()            = " + purchaseOwned.getToken());

						if (!inv.hasDetails(productID)) return;

						SkuDetails skuDetails = inv.getSkuDetails(productID);
						Log.i(tag, "	- inv.getSkuDetails() ...");
						Log.i(tag, "		.getDescription() = " + skuDetails.getDescription());
						Log.i(tag, "		.getPrice()       = " + skuDetails.getPrice());
						Log.i(tag, "		.getSku()         = " + skuDetails.getSku());
						Log.i(tag, "		.getTitle()       = " + skuDetails.getTitle());
						Log.i(tag, "		.getType()        = " + skuDetails.getType());
					}
				});
			}
		});

		btnPurchase.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				if (!isSetup) return;

				mHelper.launchPurchaseFlow(MainActivity.this, productID, 1001, new IabHelper.OnIabPurchaseFinishedListener() {
					@Override
					public void onIabPurchaseFinished(IabResult result, Purchase info) {
						boolean blnSuccess = result.isSuccess();
						boolean blnFail = result.isFailure();

						Toast.makeText(context, "mHelper.launchPurchaseFlow() - blnSuccess return " + String.valueOf(blnSuccess), Toast.LENGTH_SHORT).show();
						Toast.makeText(context, "mHelper.launchPurchaseFlow() - blnFail return " + String.valueOf(blnFail), Toast.LENGTH_SHORT).show();
						Log.i(tag, "mHelper.launchPurchaseFlow() ...");
						Log.i(tag, "	- blnSuccess return " + String.valueOf(blnSuccess));
						Log.i(tag, "	- blnFail return " + String.valueOf(blnFail));

						if (!blnSuccess) return;

						purchaseOwned = info;

						Log.i(tag, "	- info ...");
						Log.i(tag, "		.getDeveloperPayload() = " + info.getDeveloperPayload());
						Log.i(tag, "		.getItemType()         = " + info.getItemType());
						Log.i(tag, "		.getOrderId()          = " + info.getOrderId());
						Log.i(tag, "		.getOriginalJson()     = " + info.getOriginalJson());
						Log.i(tag, "		.getPackageName()      = " + info.getPackageName());
						Log.i(tag, "		.getPurchaseState()    = " + String.valueOf(info.getPurchaseState()));
						Log.i(tag, "		.getPurchaseTime()     = " + String.valueOf(info.getPurchaseTime()));
						Log.i(tag, "		.getSignature()        = " + info.getSignature());
						Log.i(tag, "		.getSku()              = " + info.getSku());
						Log.i(tag, "		.getToken()            = " + info.getToken());
					}
				}, "bGoa+V7g/yqDXvKRqq+JTFn4uQZbPiQJo4pf9RzJ");
			}
		});

		btnConsume.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				if (!isSetup) return;
				if (purchaseOwned == null) return;

				mHelper.consumeAsync(purchaseOwned, new IabHelper.OnConsumeFinishedListener() {
					@Override
					public void onConsumeFinished(Purchase purchase, IabResult result) {
						boolean blnSuccess = result.isSuccess();
						boolean blnFail = result.isFailure();

						Toast.makeText(context, "mHelper.consumeAsync() - blnSuccess return " + String.valueOf(blnSuccess), Toast.LENGTH_SHORT).show();
						Toast.makeText(context, "mHelper.consumeAsync() - blnFail return " + String.valueOf(blnFail), Toast.LENGTH_SHORT).show();
						Log.i(tag, "mHelper.consumeAsync() ...");
						Log.i(tag, "	- blnSuccess return " + String.valueOf(blnSuccess));
						Log.i(tag, "	- blnFail return " + String.valueOf(blnFail));

						if (!blnSuccess) return;

						purchaseOwned = null;

						Log.i(tag, "	- purchase ...");
						Log.i(tag, "		.getDeveloperPayload() = " + purchase.getDeveloperPayload());
						Log.i(tag, "		.getItemType()         = " + purchase.getItemType());
						Log.i(tag, "		.getOrderId()          = " + purchase.getOrderId());
						Log.i(tag, "		.getOriginalJson()     = " + purchase.getOriginalJson());
						Log.i(tag, "		.getPackageName()      = " + purchase.getPackageName());
						Log.i(tag, "		.getPurchaseState()    = " + String.valueOf(purchase.getPurchaseState()));
						Log.i(tag, "		.getPurchaseTime()     = " + String.valueOf(purchase.getPurchaseTime()));
						Log.i(tag, "		.getSignature()        = " + purchase.getSignature());
						Log.i(tag, "		.getSku()              = " + purchase.getSku());
						Log.i(tag, "		.getToken()            = " + purchase.getToken());
					}
				});
			}
		});
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		if (isSetup) {
			boolean blnResult = mHelper.handleActivityResult(requestCode, resultCode, data);

			Toast.makeText(context, "onActivityResult() - mHelper.handleActivityResult() = " + blnResult, Toast.LENGTH_SHORT).show();
			Log.i(tag, "onActivityResult() - mHelper.handleActivityResult() = " + blnResult);

			if (blnResult) return;
		}

		super.onActivityResult(requestCode, resultCode, data);
	}

	@Override
	protected void onDestroy() {
		if (isSetup) mHelper.dispose();
		mHelper = null;

		super.onDestroy();
	}
}